Messages in this thread | | | Subject | Re: Scalability requirements for sysv ipc (+namespaces broken with SEM_UNDO) | From | Mike Galbraith <> | Date | Sun, 30 Mar 2008 19:18:08 +0200 |
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On Sun, 2008-03-30 at 16:12 +0200, Manfred Spraul wrote: > Mike Galbraith wrote: > > On Sat, 2008-03-22 at 20:08 +0100, Manfred Spraul wrote: > > > > > >> just the normal performance of 2.6.25-rc3 is abyssimal, 55 to 60% slower > >> than 2.6.18.8: > >> > > > > After manually reverting 3e148c79938aa39035669c1cfa3ff60722134535, > > 2.6.25.git scaled linearly > We can't just revert that patch: with IDR, a global lock is mandatory :-( > We must either revert the whole idea of using IDR or live with the > reduced scalability.
Yeah, I looked at the problem, but didn't know what the heck to do about it, so just grabbed my axe to verify/quantify.
> Actually, there are further bugs: the undo structures are not > namespace-aware, thus semop with SEM_UNDO, unshare, create new array > with same id, but more semaphores, another semop with SEM_UNDO will > corrupt kernel memory :-( > I'll try to clean up the bugs first, then I'll look at the scalability > again.
Great!
-Mike
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